The pretreatment of bacteria source is one of the key factors affecting the efficiency of bio-hydrogen production.Prior to inoculation

cow dung compost as the natural microbial consortium is treated by following methods: (1)forced aeration combined adding sugar after infrared drying; (2)infrared drying; (3)infrared drying combined forced aeration; and (4)water immersion.The effects of the microbial community on bio-hydrogen production were investigated in a 20 L continuous stirred tank reactor (CSTR).The results showed that the maximum hydrogen production ability

hydrogen content and the rate of hydrogen production was 387.6 ml H2·g-sucrose) -1

55.5% and 0.5089 L H2·L·h) -1 at fixed sucrose concentration of 10 g·L-1

operating pH of 5.0±0.1 and the pretreated bacteria source by method (1)

respectively.The contents of acetic acid and butyric acid were more than 75% of VFAs in the terminal liquid phase by-product.Furthermore

the image analysis by PCR-DGGE technology showed that there was district difference in the number of electrophoresis band and the strength.The sample

of which the bacteria source was treated by method (1)

exhibited two maximum illumination bands

which implies that there exist two kinds of dominant microbial community.